Water and hydrogen sulfide dimers have been studied with several different density functional theory (DFT) methods using a 6-311 + + G(d, p) basis set. Geometries, energies, and QTAIM parameters were computed for different functionals and the values were compared with other ab initio and experimental results available in the literature.

In this work, first principles study of acetonitrile complexes (acetonitrile•••H-X, X=F, Cl, NH2, OH) has been carried out using electrostatic potential analysis, ab initio (MP2/6-311++g(2d, 2p), B3LYP/6-311++g(2d, 2p) and AIM theoretical calculations and these calculations confirm the hydrogen bonding interaction for these complexes. The geometrical parameters, binding energy and (3, -1) bond critical points confirm that HF donor is found to form strong hydrogen bond and NH3 donor is found to form weaker hydrogen bond for these complexes.